Rolling mills

ABSTRACT

In a rolling mill for following aluminum strip, it is desirable to apply water to the rolls on the entry side of the mill. Water should be kept off the surface of the rolled strip to avoid marking and, to this end, a moisture extraction device is arranged to collect moisture passing between the upper work roll and its back-up roll. The device includes an extractor system connected to a head assembly located in the cusp between the work roll and its back-up roll on the exit side of the mill.

This invention relates to rolling mills and in particular to rollingmills for cold rolling aluminium strip.

The final rolling stages of aluminium strip consist of rolling the stripthrough a number of rolling mill stands, sometimes arranged in tandem,so that the strip leaving the last stand is of the required gauge. Thisstrip is then coiled for subsequent use. The rolls of the mill standsare cooled by having liquid coolant applied to them on the entry sideand it has been the practice to employ kerosene as the liquid coolant.However, for various reasons, it would be preferable to use water as theliquid coolant, but it is absolutely vital to keep water off the stripon the exit side of the mill when it is coiled because water left on thesurface of the coiled strip dries and causes considerable staining ofthe strip rendering it unacceptable to many potential users.

Each of the mill stands consists of a pair of work rolls arranged oneabove the other and each work roll is backed up by a separate back-uproll. The liquid coolant is applied to both the work rolls and theback-up rolls on the entry side of the mill stands and steps are usuallytaken to contain the liquid coolant on the entry side of the stand andto limit, as far as possible, the movement of the liquid coolant to thesurfaces of the rolls at the exit side of the stands in order to preventmoisture being deposited on the strip and which may eventually causestaining of the strip.

In practice, it has been found hat moisture may penetrate between theupper work roll and its back-up roll and collect in the cusp at the exitside of the mill between the upper work roll and its back-up roll.Furthermore, even if the liquid coolant applied to the back-up roll onthe entry side is contained within a chamber which is sealed along itslength to the periphery of the back-up roll, there may be some leakagethrough the seal between the chamber and the upper back-up roll and thispermits some moisture to collect on the periphery of the upper back-uproll and be taken to the cusp between this roll and its work roll on theexit side.

It is an object of the present invention to provide a moistureextraction device for such a rolling mill by which moisture whichcollects at this cusp can be removed.

According to the present invention, for use with a rolling mill having apair of work rolls each backed-up with the back-up roll, a moistureextraction means is characterised in that it comprises a head assemblyshaped to enter into and extend along the length of the cusp between theupper work roll and its back-up roll on the exit side of the mill; anextractor system connected to the head assembly and including suctiongenerating means by which, in use, air is sucked from the cusp throughthe head assembly into the extractor system whereby moisture present inthe cusp is drawn with the air into the extractor system.

With a rolling mill fitted with a moisture extraction device inaccordance with the present invention, moisture which may collect at thecusp between the upper work roll and its back-up roll at the exit sideof the mill is removed so that it cannot fall on to the upper surface ofthe strip material where, if it is water and the strip is aluminium, itcould bring about staining of the material.

The extractor system includes ducting which connects the head assemblywith suction generating means and the ducting has quick-release jointsat its connections to the head assembly and suction generating means.The quick-release joints may be operated simultaneously. Thisarrangement of the ducting and the quick-release joints is particularlyconvenient if the head assembly is supported from the bearing chocks ofthe upper work roll so that, when the work roll is to be replaced, thehead assembly is removed with the work roll and its chocks. To enablequick-release and re-connection of the joints, the release jointsbetween the ducting and the head assembly and the suction generatingmeans can be released simultaneously, the roll changed and theconnections re-made simultaneously with the minimum of delay.

To ensure that moisture present at the ends of the cusp between the tworolls is drawn into the extractor system, it is convenient for the headassembly to include at least one nozzle at each end with the nozzlesbeing directed into the cusp in the direction from the ends thereof andair under pressure is supplied to the nozzles to blow any moisture atthe ends of the head assembly towards the central region of the headassembly where it can be readily withdrawn with the air being drawnthrough the head assembly.

In order that the invention may be more readily understood, it will nowbe described, by way of example only, with reference to the accompanyingdrawings, in which:

FIG. 1 is a sectional side elevation of part of a rolling millillustrating the present invention;

FIG. 2 is a side elevational of a rolling mill showing the ductingbetween the head assembly and the suction generating means;

FIG. 3 is a plan view of a head assembly; and

FIG. 4 is a plan of the ducting.

A rolling mill for cold rolling aluminium strip comprises a pair of workrolls 1, 3 arranged one above the other and each backed-up by a back-uproll, the upper back-up roll 5 being illustrated. The strip being rolledbetween the work rolls of the rolling mill is indicated by reference S.

At the cusp between the upper work roll 1 and its back-up roll 5 on theexit side of the mill there is a head assembly 7 which extends for thelength of the rolls. The head assembly is supported at its ends by anyconvenient means from the bearing chock assemblies 9 of the work roll.The head assembly 7 comprises a backing plate 11 having shaped endpieces attached to it which enables it to be positioned closely withinthe cusp between the rolls. The plate 11 and the end pieces support aplurality of tubes 15 which communicate with unions 17 on the plate 11and positions close to the surfaces of the two rolls. Each unionprovides a tapered socket 19.

At a position away from the cusp between the rolls there is provided onthe mill housing suction generating means, indicated generally byreference 21 in FIG. 2. This forms part of an extractor system connectedto the head assembly. Ducting 23 is provided between the suctiongenerating means 21 and each of the unions 17 on the head assembly. Theducting is supported on a movable plate 25 and it comprises two U-shapedducts 26 each having a connecting duct 27 in communication with thecentral region of the duct. The two outer ends of the ducts 26 and theouter end of the connection duct 27 each have tapered surfacescorresponding to the tapered surfaces 19 on the unions 17 and asimilarly tapered surface on a union on the suction generating means.The U-shaped ducts mounted on the plate 25 include bellow sections 26'such as to permit limited relative movement between the ends of theducts and the plate in the direction of the length of the limbs of theducts. A piston-cylinder device 28 is supported from the mill housingand is connected to the plate 25. On actuating the device 28, the plateis moved on guides whereby the ends of the ducts can be displaced in thedirection towards and away from the unions with which they connect sothat they can be quickly and simultaneously released from the unions toenable the work roll to be removed and replaced as required.

At the ends of the head assembly there are a pair of nozzles (not shown)which are connected to an air supply by a tube 30 (FIG. 3). The airnozzles are so directed that the air issuing from the nozzles is appliedfrom the ends of the cusp towards the central region thereof to blow anymoisture present at the ends of the cusp towards the pipes 15 within thehead assembly.

In use, any moisture, particularly water, which tends to collect in thecusp and which, in the absence of the invention, may fall on to theupper surface of the strip just before it is coiled, is, by means of theextractor system, removed from within the cusp through the headassembly.

I claim:
 1. A moisture extraction means for use with a rolling millhaving upper and lower work rolls and upper and lower back-up rolls eachmounted in a bearing chock assembly, said moisture extraction meanscomprising a head assembly arranged to be supported from the bearingchock assembly of the upper work roll and shaped to enter into andextend along the length of the cusp between the upper work roll and theupper back-up roll on the exit side of the mill;suction generating meanspositioned remote from the head assembly and ducting connecting the headassembly and the suction generating means, whereby moisture present inthe cusp is drawn into the extraction means, said ducting includingquick release joints at its connections with the head assembly and thesuction generating means.
 2. Moisture extraction means as claimed inclaim 1 wherein the head assembly includes an elongate backing platehaving a pair of opposite ends and a pair of opposite sides, projectionsat said ends of the plate shaped to enter into said cusp, saidprojections and one side of said backing plate together defining aspace, a plurality of unions spaced apart along the length of thebacking plate on the opposite side thereof and a plurality of tubescommunicating with the space and with each of the unions.
 3. Moistureextraction means as claimed in claim 1, characterised in that nozzlesare located on the head assembly at the ends thereof, said nozzles beingdirected inwardly of the end pieces towards the central region of thehead assembly and means for supplying air under pressure to the nozzles.4. Moisture extraction means as claimed in claim 2 wherein the ductingis connected by way of quick release joints with said unions and meansare provided for operating all the quick release joints simultaneously.5. Moisture extraction means as claimed in claim 4, wherein all theducting is mounted on a movable support plate and means are provided fordisplacing the support plate and the ducting between a first position inwhich the connections between the ducting and the unions and the suctiongenerating means are made and a second position in which the connectionsare broken.